1366 - Incorrect integer value: '' for column 'customer_id' at row 1

insert into whos_online (customer_id, full_name, session_id, ip_address, time_entry, time_last_click, last_page_url) values ('', 'Guest', 'v41fk6cip1l2o80qsntoqln412', '3.137.200.242', '1746783242', '1746783242', '/xtshop/product_info.php?info=p771_.html')

[XT SQL Error]